A. Field of the Invention
This invention relates to new nitrogenous, crosslinking compounds characterized by N,N-bis-(vinylbenzyl) substitution which comprise reaction products which are prepared from a mixture of vinylbenzyl chloride with an amine, processes for preparing said compounds, and polymerizing said crosslinking compounds to obtain polymers which are useful, for example, as ion exchange resins, flocculants, thickeners, and the like. The new nitrogenous compounds are useful as monomers and as crosslinking agents and/or function-introducing agents.
B. Description of the Prior Art
Macroreticular and gel vinylbenzyl chloride polymers which possess a tertiary amine or a quaternary ammonium functionality have been prepared in the prior art by various methods as follows: (a) They may be made by first polymerizing or copolymerizing styrene and then chloromethylating the copolymer or the polymer and subsequently aminating the chloromethyl functionality. (b) A second way of making such polymers is to polymerize a mixture of vinylbenzyl chloride and divinylbenzene in a one step process. The resulting polymer is then aminated to provide a weakly, or strongly basic resin. For further details of a typical prior art process, see U.S. Pat. No. 3,637,535 and U.S. Pat. No. 3,843,566. The chloromethylation process, although widely used to provide polymers and ion exchange resins derived from such polymers, possesses inherent disadvantages. For example, the chloromethyl methyl ether (CME) which has been widely used as a chloromethylating agent to provide reactive chloro groups on the polymer is a substance of such great toxicity that its use is contraindicated. In addition, the multistage nature of the chloromethylation process of the prior art makes it inherently more expensive than the one-step process utilized to prepare the polymers of the present invention. A disadvantage of the one-step vinylbenzyl chloride (VBC) polymerization process of the prior art is that, in order to obtain weakly or strongly basic anion exchange resins, the vinylbenzyl chloride polymers must be aminated in an additional step to provide such anion exchange resins.